Post partum urinary retention occurs in significant number of women,and it can cause permanent damage to the bladder detrusor muscle and long term complications if left untreated.PPUR goes undetected as most of the patients are asymptomatic. The incidence may range from 0.05% to 37% .In our study ,the overall incidence of post partum urinary retention was found to be 12% . The incidence of covert retention is 9% which is much more than that of overt retention which is 3%. Patients with covert retention are asymptomatic and are diagnosed by measuring postvoid residual bladder volume by ultrasound or by catherisation, These patients might go in for long term complications .Acute overdistention of the bladder leads to damage to detrusor syncitium with ischemic damage to the post synaptic parasympathetic fibres.
Overt retention can be detected as these patients will have signs and symptoms of post partum urinary retention like pain lower abdomen, inability to void, and dribbling of urine (overflow incontinence).
Previous studies have evaluated the relationship between obstetric risk factors and post partum urinary retention. In the largest retrospective case controlled study by M.Carley et al, the factors associated with clinically overt retention were studied.
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A total of 51 patients of 11,332 (0.45%) vaginal deliveries were complicated by symptomatic overt urinary retention. In most of the patients (80.4 %) the problem resolved before hospital discharge. It was shown that patients with urinary retention were more likely than control patients to be primiparous(66.7% vs 40%, p < 0.001). These patients had higher incidence of instrumental deliveries than controls (47.1% vs 12.4%, p = 0.001). The patients with urinary retention were more likely to have received regional analgesia 98% vs 68.8%;p < 0.001, and to have had a mediolateral episiotomy 39.2 % vs 12.5%;
p < 0.001. On multivariate regression analysis, only instrument assisted delivery and regional analgesia were found to be significant risk factors.
Studies have shown that primiparity was associated with more post partum urinary retention. In an observational prospective study by Liang et al, to assess the contributing risk factors and the long term impacts of post partum urinary retention, included a total of 2866 women, delivered vaginally. 114 women were classified as urinary retention group and the remaining 2752women categorized as control group.78.1% of patients who had urinary retention were primiparas
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In our study we found no association between parity and post partumurinary retention, p = 0.156, NS.
It was found that 10 out of 58 primigravidas had post partum urinary retention as compared to 2 out of 42 multigravidas with post partum urinary retention.
Instrumental delivery was significantly associated with post partum urinary retention in most of the studies. In the retrospective study by Liang et al ,a total of fifty one patients of 11,332 (0.45%) vaginal deliveries were complicated by clinically overt urinary retention. These patients had higher incidence of instrumental deliveries than controls (47.1% vs 12.4%, p < 0.001).On multivariate regression ,instrumental delivery was found to be associated with overt postpartum urinary retention.( 4 ).
In our study, we found that patients who had an assisted delivery were more prone to have post partum urinary retention. 81 patients out of 100 patients delivered normally whereas the remaining 19 patients had an assisted delivery. In our study no patients with normal delivery had urinary retention.12 patients with post partum urinary retention had assisted delivery. p = 0.000 which was statistically significant on univariate analysis.
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Regional analgesia has been associated with post partum urinary retention by several people. In women who received regional analgesia, the incidence of post partum urinary retention was 98.0% as against women who did not receive regional analgesia (68.8%, p < 0.001%).Other studies have also supported this finding . Roderick et al, did a retrospective case control study to determine the incidence of overt post partum urinary retention after vaginal delivery and to establish associated risk factors. They included 15,757 deliveries from 2001- 2005. There were 30 cases of overt post partum retention, (0.2 %) There were 120 time matched controls .The use of regional analgesia was associated with an increased risk for post partum urinary retention .( OR 6.33,CI 2.01- 19.96, p< 0.0001).In our study ,there were no patients who received regional analgesia during labour or delivery .
Episiotomy again is associated with an increased incidence of post partum urinary retention ,39.2% cases vs 12.5% control (p<0.0001) .In our study, episiotomy is not associated with post partum urinary retention.There were 71 patients who had an episiotomy during delivery. The remaining 277 patients delivered without an episiotomy. 61 out of 494 patients (12.3%) with episiotomy were diagnosed to have post partum urinary retention, whereas23 out of 277 patients without episiotomy also had post partum urinary retention.
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It was not found to be statistically significant( P = 0.093, NS).Birth canal injury, and severe perineal lacerations were found to be associated with post partum urinary retention . In a retrospective study by Ling et al, patients with extensive vaginal or perineal lacerations were associated with higher incidence of post partum urinary retention.41.2 % cases had birth canal injury and urinary retention (n = 114 ), as compared to 7.1% controls ,( n= 2752), p< 0.001 . In our study however birth canal injury is associated with increased incidence of post partum urinary retention.
There were 9 patients who sustainedbirth canal injury.Out of which ,4 patients had postpartum urinary retention.which was found to be statistically significant. (P = 0.002, S ).
Yip et al 1997, found that duration of labour>/ = 800 min was significantly associated with post partum urinary retention, p > 0.001. The other obstetric variables like parity, mode of delivery, birth canal trauma, epidural anaesthesia, instrumental delivery and episiotomy were found to be the confounding factors. They presented one hypothesis that during prolonged labour, the presenting part of the fetus may exert pressure on the pelvic floor and soft tissues, including the pelvic nerves, which may subsequentlylead to either urinary outflow obstruction by tissue oedema, or detrusor dysfunction due to neurapraxia. Our study also found that prolonged duration of labour was definitely associated with post
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partumurinary retention and the association was statistically significant p < 0. 000. The mean for the duration of labour in patients with post partum urinary retention (n =12),was 390.00 minutes. The median for the duration of labour in patients without post partum urinary retention (n = 88) was 308.07 minutes (p < 0.000) ,which was statistically significant.
Fetal birth weight has been evaluated as a causative risk factor for post partum urinary retention. It is found to be to be associated with post partum urinary retention in some studies. In our study, shows that birthweight is significantly associated with post partum urinary retention The mean birthweight of the babies in women with post partum urinary retention was 3428.25 grams whereas the mean birth weight of babies for women without post partum urinary retention was 3039.47 grams, which was found to be statistically significant (P = 0.001,S).
In our study age of the patient, as a risk factor, was not found to be significantly associated with postpartum urinary retention.. In an observational prospective study by Liang et al, to assess the contributingfactors and long term impacts of post partum urinary retention, included a total of 2866 women,delivered vaginally. 114 women were classified as urinary retentiongroup and the remaining 2752women categorized as control group. Women in the urinary retention group and control groups did not differ significantly in terms of age, and fetal birth
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weight.
In our study the mean age of the patients with post partum urinary retention was 23.50 +/-2.393 years compared to 25.09+ / - 3.027 years in those without urinary retention .( p = 0.084 NS )
In our study,we also analyzed the mode of previous delivery as an associated risk factor for post partum urinary retention .We found that the mode of previous delivery is not associated with post partum urinary retention. (P = 0.058,NS).
In a previous study by Yip et al, six hundred and ninety patients were randomized into two groups . An ROC curve was used to determine the optimum cutoff value of duration of labour for detecting post partumurinaryretention. This would then help in screening patients to detect post partum urinary retention. Using an optimal cutoff of 700 min, for the duration of labour, area under the curve ROC was 0.63, (95% CI 0.57- 0.69), which gave a specificity of 95%, sensitivity 15%, Negative Predictive Value of 86%,Likelihood ratio of negative test of 88%, Likelihood ratio for positive test was 4.9% .The sensitivity ,Positive Predictive Value, Likelihood Ratio for Positive Test could not be raised without compromise to specificity.
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In our study, duration of labour was used to plot an ROC curve and the AUC ROC was used to predict post partum urinary retention. The area under the curve was found to be 0.825 (95% CI, 0.736- 0.894), with p = 0.0001. When 320 minutes was used as the optimum cut off for duration of labour,thespecificity of the test was 61.36%, sensitivity of 100%.
There are several short term and long term complications of post partum urinary retention .Patient distress due to outflow obstruction, hesitancy, frequency, urgency,poor flow, bladder over distension causing pain and discomfort, overflow incontinence and infection are some of the immediate or short term complications .
Most of the studies have focused on the immediate post partum complications. Almost all these studies have demonstrated that, covert retention resolved spontaneously without requiring any specific intervention.
Yip et al, monitored the post void residual bladder volume of 67 women with covert post partum urinary retention (PVRBV ≥ 150ml), using ultrasound. Despite not using any form of bladder drainage as treatment, the condition resolved in all women by post partum day 4, with the majority (82%) resolving after the first day.
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Overt retention on the other hand required bladder catheterization, although the length of time post partum urinary retention persists is variable. Carley et al ,in the largest to date retrospective study of 51 women with overt post partum urinary retention, reported that the length of time required for post partum urinary retention to resolve was more than 3 days in 25.5% cases. Ten patients had persistent post partum urinary retention at the time of hospital discharge. They were successfully treated with either intermitentself –catheterization or an indwelling urethral catheter. All patients ultimately had resolution of urinary retention; the longest duration was 45 days after delivery.
In a study by Liang et al ,on the long term impacts of post partumurinary retention; the results showed that three patients out of 114 women had persistent post partum retention and long term (9 months postpartum)complaints of frequency and strenuous voiding.
Data on persistent post partum urinary retention beyond the immediate post partum period and long term complications of post partum urinary retention is scarce. Persistent post partum urinary retention is defined as the inability to void spontaneously despite use of indwelling catheter for 3 days. They studied 8402 patients for persistent post partum urinary retention after delivery.
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Four patients developed persistent post partum urinary retention, 2 of them required catherisation for 1-2 weeks. The other 2 patients, required the insertion of suprapubic catheter for 28 and 40 days respectively . On follow up by urodynamics, one month after removal of suprapubic catheters, these patients were found to have stress urinary incontinence and detrusor instability.
Follow up of our patients in this study showed that all of the 9 patients with covert retention were asymptomatic at discharge. We had only three patients with overt retention, and they had indwelling urethral catheter for 24 hours. After removal, both these women underwent scan for post void bladder volume which showed a residual urine < 150 ml. They were discharged and asked to follow up in 3 months to look for persisted urinary retention or any other complication . These 3 patients were contacted over phone and enquired about the urinary symptoms. None of them had urinary symptoms.
Bladder atony, secondary to increased progesterone during pregnancy and early puerperium may also play a role. Delayed detection or misdiagnosis of bladder over distention may therefore cause irreversible detrusor damage.
Therefore care should be taken to identify patients at risk of developing post partum urinary retention. Early diagnosis of post
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partumurinary retention, may facilitate timely intervention and therefore bladder distention and associated detrusor dysfunction can be prevented. Hence, if a woman is unable to void spontaneously after delivery they must be encouraged for early ambulation, asking the patient to listen to running water or taking a warm bath. If the patient is still unable to void, then she should be relieved of over distention by an indwelling urethral catheter for atleast 24 hours.
If the patient still has persistent post partum urinary retention after 24 hrs (ultrasound PVRBV > 150ml), she should be advised intermittent self – catheterization, till the residual volume is < 150 ml.
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